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Diffstat (limited to 'include/linux/mm.h')
-rw-r--r--include/linux/mm.h20
1 files changed, 15 insertions, 5 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f28f46eade6a..c1b7414c7bef 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -175,7 +175,7 @@ extern unsigned int kobjsize(const void *objp);
* Special vmas that are non-mergable, non-mlock()able.
* Note: mm/huge_memory.c VM_NO_THP depends on this definition.
*/
-#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP)
+#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
/*
* mapping from the currently active vm_flags protection bits (the
@@ -399,8 +399,18 @@ static inline void compound_unlock_irqrestore(struct page *page,
static inline struct page *compound_head(struct page *page)
{
- if (unlikely(PageTail(page)))
- return page->first_page;
+ if (unlikely(PageTail(page))) {
+ struct page *head = page->first_page;
+
+ /*
+ * page->first_page may be a dangling pointer to an old
+ * compound page, so recheck that it is still a tail
+ * page before returning.
+ */
+ smp_rmb();
+ if (likely(PageTail(page)))
+ return head;
+ }
return page;
}
@@ -757,7 +767,7 @@ static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
{
- return xchg(&page->_last_cpupid, cpupid);
+ return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
}
static inline int page_cpupid_last(struct page *page)
@@ -766,7 +776,7 @@ static inline int page_cpupid_last(struct page *page)
}
static inline void page_cpupid_reset_last(struct page *page)
{
- page->_last_cpupid = -1;
+ page->_last_cpupid = -1 & LAST_CPUPID_MASK;
}
#else
static inline int page_cpupid_last(struct page *page)